archiver is a daemon which will process a specified text file,
each line of which is a URL, and will (randomly) one by one request that
the URLs be archived or spidered by http://www.webcitation.org,
http://www.archive.org, and http://www.wikiwix.com for future reference.
(One may optionally specify an arbitrary sh command like wget to download URLs locally.)

Because the interface is a simple text file, this can be combined
with other scripts; for example, a script using Sqlite to extract
visited URLs from Firefox, or a program extracting URLs from Pandoc
documents. (See http://www.gwern.net/Archiving%20URLs.)